Payment process for buying a resale plan.

I want to buy a resale flat in Kolkata and owner of that flat stay in Bangalore. For payment process, i share the following plan with seller: 1. We will pay 5000 as token money at the time of document collection. Then i will get the searching/scrutiny done in next 1 week. 2. On a successful scrutiny, we will get sales agreement done with 1% or 2% of property value(50 Lk) as per standards . 3. Then we will apply the for loan and once we get loan approved, rest of the amount will be paid at the time of registration. But Seller is asking for below payment plan: This is a ready to move and already registered flat. Amount wise we would like to go as follows. 1. Booking amount 1L to hold the property for you. This amount will be completely refundable. 2. Agreement of sale amount 2L. 3. Remaining amount on date of handover registration. No cash transaction and strongly recommend to appoint a lawyer at your end. We will also share our lawyer details to complete the agreement and legal things smoothly. Now i am not sure how fair it is to pay 1 Lk before doing scrutiny. Rs 5000 is okay and for this risk can be taken. But 1 Lk is a big amount to be in risk in case of unsuccessful deal due to any reasons in future. Please suggest how to proceed. Thanks & Regards, Vivek